M(X)=[blue]1*0,1+2*0,25+3*0,2+4*0,15+5*0,3=3,3[/blue]
D(X)=M(X^2)-(M(X))^2
M(X^2)=x^2_(1)*p_(1)+x^2_(2)*p_(2)+x^2_(3)*p_(3)+x^2_(4)*p_(4)+x^2_(5)*p_(5)
M(X^2)=[red]1^2*0,1+2^2*0,25+3^2*0,2+4^2*0,15+5^2*0,3=12,8[/red]
D(X)=[red]12,8[/red]- ([blue]3,3[/blue])^2= считайте
σ (X)=sqrt(D(X))